40 Argon/ 39 Argon Dating of Pseudotachylyte from Cenozoic and Mesozoic Detachment Faults and Reverse-Sense Mylonite Zones, Southern California: Methodology and Interpretation

9814779安盛假玄武岩是一种由细碎围岩和熔体组成的非均质混合岩，可能是由于断层运动过程中的高瞬时摩擦加热而形成的。尽管物质非常复杂，但从理论上讲，它确实提供了测定活动断裂作用年龄的可能性，假设它是在断裂过程中产生的，并且某些放射性时钟系统在假硅质岩形成期间被重新设置。这个项目将通过研究几个同位素测年系统、理论扩散模型和使用天然和人造材料的校准技术来解决这个问题。预计结果将有助于理解假玄武岩的形成，并为如何利用它来确定断层运动的时间提供洞察力。

9814779Axen Pseudotachylyte is a type of fault rock consisting of a heterogeneous mixture of finely cominuted wall rock and melt likely caused by high transient frictional heating during fault movement. Although very complex material, it does theoretically offer the possibility of dating active faulting, assuming that it is produced during faulting and that some radiometric clock system is reset during pseudotachylyte formation. This project will address this problem by investigating several isotopic dating systems, theoretical diffusion models and calibration techniques using natural and artificial material. Results are expected to help understand pseudotachylyte formation and to provide insight into how it might be used to date fault movements.***